Nodulizing apparatus



June 20; 1939. K.IMIDDELBQE 2,162,782

NODULIZINGAPPARATUS I Filed April 9; 1936 2 Sheets-Sheet 1 INVENTOR 4 MMAQ ATTORNEYS June 20, 1939. K, WDDELBCQE 2,162,782

NODULIZING APPARATUS Fi led April 9, 1956 2 Sheets-Sheet 2 ATTORNEYS or'slurry, involves a Patented June 20, 1939 UNITED STATES area-:82

' NODULIZING APPARATUS Kristian Middelboe,

Frederiksberg, near Copenhag en, Denmark, assignor to F. L. Smidth &

Company, New York, N.

New Jersey Application April Y., a corporation of 9, 1936, serial No. 13,411

In Great Britain April 11, 1935 3 Claims. "(01. 259-12 This invention relates to the treatment of finely divided materials for the purpose of forming them into nodules or porous'masses, which are suitable for burning. in rotary kilns or on grates, or for other similar treatment. The invention includes both a' method and an apparatus by which the conversion referred to may be carried on rapidly and continuously, and, since the principles of the invention may be applied to special advantage in the nodulizing of cement raw material prior to its being burned ina rotary kiln, an embodiment.

of the invention suitable for that purpose willv be illustrated and described for purposes of explanation. It is to be understoodyhowever, and 15 will be readily apparent, that the utility of' the invention is not limited to the treatment ofthat pa-ricular material and that it may be employed for the conversion of various materials of: which cement raw material is merely one example. I At the present time, cementraw material has been nodulized before burning by treatment in an apparatus which frequently consists of a vessel, such as a trough, drum, or the like, within which there is a stirring element moving close to the stationary walls of the vessel. In order todrive this stirrer, a considerable amount of power isgrequired, and only a small part of the power is efully employed in the kneading operation, which efiects the nodulizing, while the greater proportion is consumed in overcoming frictional resistance, particularly; the friction between the stirrer and the crust of materialwhlcli gradually accumulates on the wall of the vessel. In the use of such an apparatus, it is necessary 5 to regulate the moisture content of the material in order to obtain a product of the correct grain size, in the case of nodules, and of the desired porosity, when either nodules or porous masses are produced. Accordingly, it is customary to add 40 water or'slurry to the dry material in the vessel of the apparatus, and the greater the quantity of the material undergoing treatment, the longer a is the period thatmust elapse after the '?addition of the wateror'slur'ry before the product can be discharged. Ordinarily, the quantity of material undergoing treatmentin the-apparatus must be considerable if a' substantial output is to be obtained, and since the regulation of the moisture content of the material by the addition of water considerable delay inthe conversion of the material in the apparatus into the desired form, 7 h a prolonged operation consumes. a substantial amount of power.

The present invention is,- accordingly, directed 55 to I the provision of a method and apparatus I consumed is rial on the support and do not come in contact '-withjcrusts or which overcome the objections to the'apparatus heretofore employed for the conversion of wet or 'dry materials into nodules or porous muses. i according to the invention, the material to he treated is spread in a relatively layer on a 5 support and is there subjected to the action of stirring or mixing devices, these devices and the support having a relative movement during the stirring operation. Preferably, the support takes the form of a conveyor, that is, the supporting surface travels to carry the' material to the stirring devices and continuously presents a clean surface on which the fresh material may be distributed in a relatively thin layer for the stirring-operation, but, if desired, the support may 1. be stationary and the stirring devices may move over it, a discharge'device heingthen provided for .removing the mixed material from the' support so that the fresh material'is on a clean part of the support'where the stirring takes place. I

The material that is to undergo treatment in the new apparatus is brought to the desired consistency by the addition of a liquid or a dry material,- as the case may he. Thus, .for example, ii. the material is dry, water, --slurry, or other suitable liquid may be added to bring its moisture content to the desired value before the stirring is carried on, but if the materialis initially in the form of slurry or contains a relatively high percentage of moisture, dry material is added,

\ With either form of the apparatus, the power v much-less than that required for the operation of the devices heretofore used, the reason being that in the apparatus of the invention, the surface on which the stirring operation is carried on, is cleaned and stirred material'- does not accumulate thereon, so that the mixing devices constantly act on massesof stifiened material. over, since only small quantities of material are ,treated at a time, any adjustment in the moisture contentby the addition of dry or liquid to the mass undergoing treatment does not delay the operation, because the added material or liquid is taken up quickly, anda constant flow of treated material f uniform characteristics can beobtained; In cement manufacture, this is 101- a, ticularly important since it makes and economical operation of the kiln. w .i 7 The apparatus of the invention mayinclude one or morestirringormixingdevicaasdesirflas, for instance, the emeritus may include one or n 1 the material from the support after it has been acted on by one of the stirring devices and before the next device comes into action, means may be provided to loosen the layer of material from a 7 layer of material 'thus 35 I in hell veyor belt between the feed hopper ilrst of the stirring devices |s.. H The apparatus shown diagrammatically in Figthe support, turn it upside down, and distribute it again upon the support in a thin layer.

For a better understanding of the invention, reference may be had to the accompanying drawings which. illustrate various forms of apparatus constructed in accordance with the principles of the invention and suitable for the practice of the new method.

In these drawings, Figure 1 is a view partly in elevation and partly in section oi one form of the new' apparatus;

Figure 2 is a. fragmentary sectional view on the line 2-2 of Figure 1, the parts'being shown on a larger scale;

Figures 3 and 4 are plan and elevational views, respectively, oia modified form of the apparatus;

Figure 5 is a sectional view of anothermodified form of the apparatus; and

Figure 6 is another sectional view on the line 66 of Figure 5.

Referring to the drawings, and in particular to Figures 1 and 2, the apparatus is illustrated as comprising a feed hopper ill by which the ma terial ii to be treated is discharged in a thin layer I! on an endless belt conveyor l3, the upper run of which is supported by a plate l4. The I distributed over the belt is carried by the latter to the stirring devices generally designated l5 and may be kept from being thrown off the belt at the sides thereof during the mixing operation either by fixed vertical walls It disposed above the belt l3 near the edges thereof or by means of a pair of vertical belts, one on either side of the belt l3, such, for example, as the belt l1, illustrated in Figure 2, as passing about a vertical pulley 8.

A frame IQ of suitable construction is supported over the conveyor belt I 3 and in this .frame are mounted a plurality of the stirring or mixing devices l5, three such devices being employed in. the apparatus shown in Figure 1. Each of these devices comprises a vertical shaft provided'with a bevel gear 2 meshing with a similar gear 22 on a horizontal shaft 23 mounted in suitable supports on the frame IS. The shaft 23 is driven through bevel gearing 24 by a crossshaft "provided with a drive pulley 26 rotated by a motor 28, which,

through a drive belt 21 desired, may

also beemployed to drive the conveyor belt l3."

Each of the shafts 2| is supported the frame' II, and at its lower end, each shaft is provided with a drum II from which project radialstin'ingarmsfl.

The moisture content of the material undergoing treatment is controlled by the addition ofxliquid or dry material which is supplied to the layer of material on the conveyor belt, ll from a vessel I; which dischargcsupon the con:-

ures 3 and! is generally similar to that shown in Figures 1 and 2, except that the stirring-and mixing operations are carried on in two-stages and the material is turned upside down on the belt between these stages. This form-of the apparatus includes two sets of mixing devices Ii,

bearings-29 in a housing 30 supported in ad he f 2,162,782 a plurality of rotary shafts, each provided with with two devices to each set, and between the two sets of mixers is a plow 34 having a nose 34 which lies close to the surface of the conveyor. As the conveyor moves along, the material which has been subjected to a preliminary mixing operation is removed from the conveyor belt and then discharged upside down upon the belt, after which the material passes to the mixers of the second set for the final mixing operation. The use of such an apparatus insures that all the material will be subjected to thorough stirring and mixing actions, and the apparatus is particularly useful in the treatment of those materials which have a tendency to stick to the conveyor.

The apparatus illustrated in Figures -5 and 6 is 01 the type in which the support is stationary and the mixing devices move relative thereto. In this apparatus, a supporting frame 35 is mounted pivotally at 36 on a central pier 31, and the outer end of the frame is supported on one-or more wheels 38 running on a rail 39 on,

dry material to be added to obtain the desired moisture content in the treated material. Also mounted on the frame are a plurality of mixing devices 43, including stirring arms on a vertical shaft,.these devices being'driven by gearing from 1 a shaft 44 which is rotated through suitable reduction gearing by'a motor 45 on theframe. The shaft 44 carries a gear 46 at its outer end meshing with a similar ,gear 41 on the axle of one of the wheels =38, the motor 45 'thus being employed both to rotate the frame 35 and drive the stirring devices.

The table 48 for supporting the material undergoing treatment is mounted on the upper end of the pier 31 and takes the form of asultable circular plate strengthened by stiffening ribs-49 on the under surface, In order to prevent the material undergoing treatment from being thrown off the support by the mixing devices, a vertical baflle wall!!! is mounted on the under surface of the frame 35 near the edge of the table any suitable means well known in the art and not illustrated, The bin 4| preferably has its forward wall extending down close to the surface of the table and 'on the front face of this wall, a

radial scraper I2 is provided, which serves to" force the treated material 01! the table. The rear wall of the bin-4| is provided with an opening it through which the material is discharged upon the table.

In the'operationot the, apparatusshown in 5 andfi, the suppo t g frame moves in the direction oi'the argowin gure 6; and during its movement, the material charged upon the table through the opening 53 and the previously treated materiai is thrown oif the table by the scraper 52. The material, for

example water, employed for regulating the moisture content of the material undergoing be treated is distreatment, is then discharged from the container 42 upon the thin layer of material on the table, and the two materials are then thoroughly stirred and mixed together by the action of the mixing devices 43.

In both forms of the apparatus, it will be apparent that the material to be treated is always discharged upon a. clean surface, and the treated material is continuously carried out of the apparatus so that no accumulations of material which become stiif and hard and make difiicult the operation of the stirring devices are formed. Since the material to be treated is discharged on the supporting table in a thin layer, mixed by the mixing devices, and since the moisture content can be readily controlled and the added quantities of water or dry material are quickly taken up, the apparatus operates continuously and with a regular and constant output.

I claim:

1. Apparatus for treating finely divided material in moist condition'which comprises the combination of aplane support, means for distributing material to form a relatively thin layer of substantially uniform thickness, a device disposed adjacent said support for mixing and stirring the moist material thereon, said device including a vertical shaft and horizontal arms supported thereby and movable close to the surface of said support, means it is thoroughly be treated on said support to" located in advance of the mixing and stirring device for regulating the moisture content of the material to place it in the tween said device and support longitudinally of the layer of material to cause said device to act on the moist material progressivelyand to cause the treated material to be continuously withdrawn from the range of action of said device.

2. Apparatus for treating finely divided mate rial in moist condition which comprises the combination of a travelling plane support, means for distributing material to be treated on said support to form a relatively thin layer of substantially uniform thickn a series of devices disposed adjacent said support for mixing and stirring the moist material each of said devices' including a vertical shaft and horizontal arms supported thereby and movable close to the surface of said support, means located in advance of said devices for regulating the moisture content of the material to place it in the desired moist condition, said support advancing the moist material to said devices in succesflon and withdrawing it therefrom.

accordance with claim. 2 pro- 3. Apparatus in vided with means acting on the material between the said devices to loosen the support.

I KRISTIN E.

material from the v desired moist condition, Y

and means for producing relative movement be- 

